Slitting knife holders with fluid actuating means for the slitters



A 1951 w BURK ETAL 2,997,906

SLITTING KNIFE X-iOLDERS WITH FLUID ACTUATING MEANS FOR THE SLITTERS Filed Nov. 21, 1957 3 Sheets-Sheet 1 Aug. 29, 1961 w, U K ET AL 2,997,906

SLITTING KNIFE HOLDERS WITH FLUID ACTUATING MEANS FOR THE SLITTERS Filed Nov. 21, 1957 3 Sheets-Sheet 2 INVE N TORS 21.13

Aug. 29, 1961 w. BURK ET AL 7,

SLITTING KNIFE HOLDERS WITH FLUID ACTUATING MEANS FOR THE SLITTERS Filed Nov. 21, 1957 3 Sheets-Sheet 3 Fig.5

INV EN TORS' W. Bqrk P. W/ngen w ATTORNEYS,

2,997,906 SLITTING KNIFE HOLDERS WITH FLUID ACTU- ATING MEANS FOR THE SLII'IERS Willy Burk, Vilkerath near Overath, Bezirk Koln, Germany, and Peter Wingen, Heiligenhaus, near Overath,

Bezirk Koln, Germany Filed Nov. 21, 1957, Ser. No. 697,906 Claims priority, application Germany Nov. 28, 1956 1 Claim. (Cl. 83-506) For the mechanical severing of foils or webs of tough material for example the cutting of adhesive plaster strips for wound bandages rotating circular knives are used, the sharpened edges of which at a spacing corresponding to the desired breadth of strip are pressed against a steel pressure roller which drives them and which knives cut through the web of material running in between. The narrowness of the strips to be produced is limited by the axial dimensions of the knife holders and there is therefore a need to keep these dimensions as small as possible. On the other hand in order to attain simple and rapid operation pneumatic or hydraulic application of the knives after the threading in of the web to be severed is desirable and in order to obtain the necessary cutting pressure without excessive intensity of pressure of the medium as large as possible an effective area of the control piston is desirable which is a requirement exactly contrary to the first mentioned requirement of small dimensions in the direction of the axis of the knives.

In the slitting knife holder according to the invention the two requirements are nevertheless satisfied ina surprisingly simple manner by the control cylinder as seen from the pressure roller being arranged above the knife and parallel to it and of flattened box form, the smaller diameter lying parallel to the axis of the knife. By this novel shaping and arrangement of the control cylinder, with an adequate cross section a dimension in the direction of the knife axis can be attained smaller than achieved hitherto; this dimension can easily be reduced to mm. whereby the slitting of strips of corresponding narrowness is made possible.

If the knife holders are arranged staggered peripherally and axially in relation to the pressure roller strip breadths which are substantially still smaller can be obtained.

The knife according to the invention is surrounded and guided by a flat frameor box-form carrier with as small clearance as possible, when the control cylinder can be secured in the open upper end of the carrier so that a simple compact unit is obtained. In order to utilize the space available to the best advantage the external side walls of the control cylinder can lie in continuation of the carrier. In order to facilitate the mounting and servicing of the knife holder the control cylinder can be releasably attached to the carrier by cotter joints and/ or screws and the knife can be journalled in the ends of the limbs of a flat fork guided in grooves in the carrier, the other end of the work being connected to the piston.

To return the piston, helical compression springs can be provided say in recesses in the upper end of the frame which bear on the underside of the piston in the return direction.

The carrier can be adjustably held together by screws on one side with the interposition of a yielding slotted strip of synthetic material to such an extent that its inner r 2,997,906 Patented Aug- 1961 walls guide the knife with no clearance in order to relieve the fork of tipping forces.

The carrier can be provided with lockable holding members for securing to a prismatic or cylindrical knife beam, which holding members can themselves, or together with the carrier, be exchangeable in order to enable the knife holder to be attached to dilferent knife beams.

The invention will be further described with reference to examples which are diagrammatically illustrated in the accompanying drawings.

FIGURE 1 is a side elevation of a knife holder according to the invention,

FIGURES 2, 3, and 4 show the same knife holder as FIGURE 1 but with different holding members for attachment to a knife beam.

FIGURE 5 is an elevational view in section showing a pair of knives in working position and directed to a workpiece.

The slitting knife 1, with the sharpened slitting edge 2 is journalled in bearing members 3 at the outer ends of a flat fork 4. The fork limbs are guided in shallow internal grooves 5 in carrier plates 7 which enclose the central bossing 6 of the knife 1 without play so that the knife with the fork and with a piston 8 attached to the upper end can move axially in relation to a flat shallow box form cylinder 11 under fluid pressure applied through a hat leather or like packing 9 in the direction towards the pressure cylinder or under the counter pressure of helical springs mounted in recesses 10 in the opposite direction. The cylinder is shown in outside view in the figures; its outer side Wall 12 lies in continuation with the frame plates 7 of the carrer while its inside wall is of say oval cross section. In the cylinder cover is a supply aperture 13 for the pressure medium which can conveniently be a tapped hole in a boss (FIGURES 2, 3 and 4) into which a corresponding supply pipe can be screwed. The hat leather 9 is made relatively thin as it is supported over its whole surface by the piston 8 of the fork 4. The cylinder 11 has lugs 14 engaging between the two plates 7 of the carrier and each of these is releasably secured by a single screw 15.

The right hand side of the carrier constituted by the two plates 7 has these two plates held together by two adjusting screws 17, a longitudinally slitted elastic strip 16 of synthetic material being interposed, whereby the clear space between the two plates can be so adjusted that the plates embrace the bossing 6 of the knife 1 just Without play so that the bearings 3 are relieved of tipping forces when the knife is pressed against the pressure roller.

Elsewhere the two frame plates 7 are fixed together by various rivets 18.

On the left hand side a holding device 19 with a locking screw 20 is formed on the frame formed of the two plates 7 (FIGURE 1). FIGURES 2, 3 and 4 show different forms of holding member 19 19 and 19a for securing the knife holder to various prismatic or cylindrical (FIG- URE 4) knife beams. A cylindrical beam permits axial and tangential adjustment.

The outer ends of the fork 4 have longitudinal slots 21, the lower widened ends of which resiliently hold the bearings of the knife shaft.

Referring now to FIGURE 5, reference character 31 designates a workpiece to be cut or a steel roller for transporting goods to be cut, and reference character 33 indicates a beam having ofisets to receive the holding devices 19 (FIGS. 1, 2 and 3). The knife holders are shifitable parallel to the longitudinal axis of the beam, and are lockable in selected positions whereby the cutting widths are selectable. The minimum width is the axial dimension of a single knife holder.

We claim:

A hydraulically controlled knife having a minimum width comprising in combination a rotatable blade, a pair of members arranged on each side of the knife and forming a narrow supporting frame, a chamber of flat box form fixed to said members above said blade, the smaller diameter of said chamber being parallel to the axis of rotation of said blade, each external side wall of said chamber '4 lying substantially in a common plane with each external side wall of said supporting frame whereby the chamber dimension defines the thickness of the frame, a fork member carrying a knife within the said narrow supporting frame, and a piston on the end of said fork member disposed within the said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 908,284 Langston Dec. 29, 1905 1,579,995 Aubuchorrt Apr. 6, 1926 2,712,852 Carter July '12, 1955 

